The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A DCT (Dual Clutch Transmission) includes a clutch actuator for controlling two clutches therein and a shift actuator for shifting gears so that a controller shifts gears by appropriately operating the clutch actuator and the shift actuator, depending on driving situations of a vehicle.
The clutch actuator is usually driven by a motor equipped with a hall sensor, so the position of a clutch is directly determined on the basis of a signal from the hall sensor and whether the clutch can be controlled is diagnosed on the basis of whether the signal is normal.
In the related art, when a signal having a wrong pattern or a wrong order is received from a hall sensor of a motor for a clutch actuator, a problem is sensed, and whether the motor has broken down is checked by applying a test pulse to the motor.
FIG. 1 is a graph exemplifying a case when a test pulse is applied, as described above, in which an error was sensed from a hall sensor of a motor for an even-numbered clutch actuator while a vehicle creeps backward with an even-numbered shaft clutch engaged.
In order to diagnose whether there is a malfunction when a hall sensor error is sensed, a test pulse is applied to a motor, and when it is determined that there is no malfunction, a clutch is engaged again in FIG. 1. Further, in FIG. 1, the actual stroke of an even-numbered shaft clutch going with an even-numbered shaft clutch target stroke drops from the target stroke, so a vertical vibration test is performed so the actual stroke approaches back to the target stroke.
In this situation, when the actual stroke of the clutch approaches back to the target stroke after the test is finished, we have found that a shock is generated by a sudden change of the clutch stroke and can be recognized by fluctuation of the curve showing the numbers of revolution of the even-numbered input shaft.
Obviously, a severe shock may considerably deteriorate riding comfort due to vibration of a powertrain and may even stop an engine.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.